I am not a PT, but If you have a dumbbell laying around or anything round with some weight I would do "finger curls". I do them after wrist curls. Seeing how Tenosynovitis is inflammation I have found that super lightweight, but frequent use of the muscle and tendons fixes the issue quicker. Has worked for me on my elbow before with obviously a different exercise.

Beyond that carbon bars or forks may help, a suspension stem may help, bigger tires will help. However if you don't fix the issue that pain will be lingering in the back of your head. If it hurts when you stand you won't push as hard, so I would focus on fixing it first.